General changes:
- addPointScalars and addPointVectors now are merged into new `addPointArray()` method.
- addCellScalars and addCellVectors now are merged into new `addCellArray()` method.
- added `mesh.isobands()` to produce color bands for scalars in a mesh, analogous to `isolines()`
- completely revised `addScalarbar` and `addScalarBar3D` which now works also for volumes.
- can export a full html page with `k3d` with `exportWindow("page.html")`
New `application` module contains more elaborated and high level functionalities:
- `Slicer()` to generate a ``Plotter`` window with slicing planes for the input Volume.
- `Slicer2d()` creates a 2D window with a single balck and white slice of a Volume, which can be oriented arbitrarily in space.
- `RayCaster()` generates a ``Plotter`` window for volume rendering using ray casting.
- `IsosurfaceBrowser()` generates a ``Plotter`` window for Volume isosurfacing using a slider.
- `Browser()` generates a ``Plotter`` window to browse a list of objects using a slider.
In `backends` module for jupyter notebooks:
- Updated `k3d` interface to add mesh and volumes names in the rendering menu
- Improved rendering for lines.
In `volume` module:
- added `slicePlane()` to slice a volume in arbitrary orientation